Back-to-school shots

(CNN) -- Did your child get all of his or her shots before school started? Numerous states are doing away with exemptions that allowed parents to get around vaccination requirements

Vaccination requirements for public schools were only exempted in some states due to medical, religious or philosophical reasons but following a measles outbreak at Disneyland in California in December, some states are abandoning those exemptions.

California joins West Virginia and Mississippi in requiring all children to get vaccinated, making exceptions only for medical issues. Forty-seven states permit waivers for religious reasons and 18 for philosophical objections.

Some parents were choosing not to vaccinate in recent years, citing concerns about autism, although numerous studies have failed to show any link.

New studies show higher vaccination rates for kids in states that limit exemptions or make the exemptions much more difficult to obtain.